Network automatic discovery method and system

Abstract

An automatic network discovery method and device enables network peer nodes to discover one another. A node entering a network has the burden of initiating a connection to peers potentially existing on the network. The incoming node and potential peer nodes each keep a persistent list of at least one potential peer node called a seed list, which is used at startup or restart to initially populate a peer list also kept by each node. The incoming node sends a connection request to the potential peers in its peer list. Through the connection requests and responses to the requests from the potential peer nodes, nodes exchange connection information regarding one another and other potential peer nodes on the network, which is stored in their respective peer lists.

1 . A method for node discovery in a network performed by each of a plurality of peer network nodes linked in the network, comprising:
 maintaining at a network node a persistent list containing at least one remote peer node address;   copying each remote peer node address stored in the persistent list to a peer list stored at the network node;   sending a connection request message to each remote peer node in the peer list, wherein said connection request message contains any remote peer node address stored in the peer list of the network node having an indication of an established connection to one of the plurality of peer network nodes;   receiving a connection request reply from at least one said remote peer node to which a connection request message was sent, each said reply containing any address stored in a peer list at the responding remote peer node having a status indicator indicating a connection established between the responding remote peer node and one of the plurality of network peer nodes;   adding any address contained in any received reply to the peer list of the network node, if that address is absent from the peer list of the network node;   adding the address of any responding remote peer node to the peer list of the network node; and   providing, for each added responding remote peer node address, a status indicator indicating that a connection has been established between the network node and that responding remote peer node.   
   
   
       2 . The method of  claim 1 , further comprising:
 determining whether each said remote peer node at each address in the peer list is reachable; wherein sending said connection request message is performed only to those remote nodes determined reachable.   
   
   
       3 . The method of  claim 2 , wherein determining whether each remote peer node is reachable comprises:
 sending a probe message to each remote peer node address copied into the peer list; and   receiving a return message in response to the probe message.   
   
   
       4 . The method of  claim 1 , further comprising:
 periodically sending a presence message to each remote peer node address stored in the peer list of the network node having the status indicator indicating that a connection has been established.   
   
   
       5 . The method of  claim 1 , further comprising:
 monitoring a time period between incoming presence messages sent from each remote peer node having an address stored in the peer list of the network node that has the status indicator indicating that a connection has been established.   
   
   
       6 . The method of  claim 5 , further comprising:
 if any monitored time period exceeds a predetermined value, determining whether the corresponding remote peer node is reachable; and   removing the corresponding remote peer node from the peer list if determined to be unreachable.   
   
   
       7 . The method of  claim 1 , further comprising:
 monitoring a time period between each said connection request and connection request reply, and if the time period exceeds a predetermined value before receiving a connection request reply, determining whether the corresponding remote peer node to which the request was sent is reachable; and   removing the corresponding remote peer node from the peer list if determined to be unreachable.   
   
   
       8 . The method of  claim 1 , further comprising:
 receiving a connection request message from at least one said plurality of peer network nodes, each said request containing any address stored in a peer list of the sending peer node having a status indicator indicating a connection established between the sending peer node and another one of the plurality of network peer nodes.   
   
   
       9 . The method of  claim 8 , further comprising:
 sending a reply to the sender of each said received connection request, each said reply containing any remote peer node address stored in the peer list of the network node having an indication of an established connection to one of the plurality of network peer nodes;   adding the address of each sender of a connection request to the peer list of the network node; and   providing, for each added sender address, a status indicator indicating that a connection has been established between the network node and that sending node.   
   
   
       10 . The method of  claim 3 , further comprising:
 monitoring a time period after sending each said probe message, and if the time period exceeds a predetermined value before receiving a return message, removing the corresponding remote peer node from the peer list.   
   
   
       11 . The method of  claim 2 , wherein the probe message is a Ping command.